1. How do I make every new file I make have its default syntax theme (and type) set to PHP? (not it's plain text)2. Is there a way to preview PHP files (just like Dreamweaver's F12 preview thingy) with Sublime?

1. How do I make every new file I make have its default syntax theme (and type) set to PHP? (not it's plain text)

Can't do it right now, or at least I am not aware of this feature... Good news is that:it is possible with a plugin. Hook into onNew(view) event and set syntax as PHP, shouldn't be too hard (but then again you being new to sublime I guess it makes it hard )

2. Is there a way to preview PHP files (just like Dreamweaver's F12 preview thingy) with Sublime?

If I recall correctly f12 in dreamweaver previews current file in default browser... if that's the case yes you can do that in sublime, just right click on the file and select "open in browser", in sublime *almost* everything is configurable so of course you can bind that to f12 if you wish so, the command is openInBrowser put that in your user keybindings

Another thing that I can't figure out if it's an options thing or a default behavior thing is the fact that the project's file selector dialog wont show the NEW files being made after the project was last opened.

The only workaround is to actually close the project and re-open it.

I am sure auto-populating the dialog with the new files would also come in handy.